Alkyl polyglycoside derived sulfosuccinates

ABSTRACT

The invention relates to a series of polyglycoside derivatives that contain water-soluble sulfosuccinate groups introduced into the molecule by reaction with the hydroxyl groups present in the starting polyglycoside molecule, with the chloro material. The preferred products have more than one water-soluble group per molecule and are made with mild reagents to avoid discoloration and mal odor. The most preferred products have between 2 and 3 functional groups per molecule.

FIELD OF THE INVENTION

The present invention relates to a series of polyglycosidesulfosuccinates that contain water-soluble groups introduced into themolecule by reaction with the hydroxyl groups present in the molecule.The preferred products have more than one water-soluble group permolecule and are made with mild reagents to avoid discoloration and malodor.

Commercial alkyl polyglycosides generally have a low degree ofpolymerization of polysaccharide, in the molecule. This results in amolecule that is of limited water solubility. The present invention isaimed at functionalizing the hydrophobic alkyl polyglycoside, byincluding in the molecule phosphate, sulfate, sulfosuccinate, andcarboxylate functionalities. These products have been called “alkylglycosides, alkyl glycosides, alkyl polyglycosides or alkylpolyglycosides” by many different authors. All refer to the samemolecules.

BACKGROUND

Alkyl polyglycosides have been known for many years, having been firstsynthesized in the early 1900 by Emile Fischer. Despite this, theproducts were of little commercial interest until much later.

U.S. Pat. No. 4,393,203 issued Jul. 12, 1983 to Mao et al, incorporatedherein by reference, disclose that long chain fatty alcohols can beremoved from alkyl polysaccharide products in thin film evaporators toachieve fatty alcohol levels of less than about 2% without excessivediscoloration of the alkyl polysaccharide. This allowed for a morecosmetically acceptable product to be developed that is more surfaceactive. The presence of the free fatty alcohol in the mixture, allowsfor a more water-soluble product, by removing the water insolublealcohol.

One of the most significant patents is U.S. Pat. No. 5,003,057 issuedMar. 26, 1991 to McCurry et al incorporated herein by reference,provides for a process for preparing glycosides from a source ofsaccharide moiety and an alcohol in the presence of a hydrophobic acidcatalyst is provided. An example of such a catalyst isdinonylnaphthalenemonosulfonic acid. The use of such catalysts providesa number of process advantages, which includes the reduced production ofpolar by-products. Preferred glycosides produced by the process arehigher alkyl glycosides useful as surfactants.

U.S. Pat. No. 3,598,865 (Lew) discloses the production of higher alkyl(C.₈–C₂₅) glycosides from a monosaccharide or source thereof and ahigher monohydric alcohol in the presence of a latent solvent (loweralcohols) and an acid catalyst selected from the group consisting ofsulfuric acid, hydrochloric acid, phosphoric acid, phosphorous acid,toluenesulfonic acid, and boron trifluoride.

U.S. Pat. No. 3,219,656 (Boettner) discloses a process for producing ahigher alkyl glycoside by reacting glucose with methanol in the presenceof a macroreticular-structured sulfonic acid resin, anhydrous and in theacid form, to produce methyl glycoside which is reacted withoutisolation with butanol to form butyl glycoside and which in turn isreacted with a higher alcohol to form a surface active higher alkylglycoside.

U.S. Pat. No. 3,839,319 (Mansfield) discloses a process for producingalkyl glycosides by direct, acid catalyzed reaction of a higher alcoholand a saccharide. The acid catalysts are mineral acids such ashydrochloric and sulfuric, and sulfonic acid exchange resins

None of the patents referenced above provide for a molecule that has thenecessary water soluble group incorporated to overcome the lack of watersolubility, greasy drying feel that alkyl glycosides have on the skin.The current invention is directed toward a mild aqueous reaction of achloro hydroxypropyl intermediate which is stable in and does not reactwith water. In order to achieve this, an anhydride is not a possiblereactant. This results in a specific linkage group to achieve this goal.The direct reaction of the APG or any sugar with maleic anhydride underaqueous conditions would not work, because in aqueous solution or theanhydride would open as shown;

The Invention

The present invention relates to the finding that the reaction of therather hydrophobic alkyl polyglycosides with the proper reagent resultsin molecules that have improved water-solubility and consequentlyovercome many of the shortcomings of the alkyl polyglycosides itself. Itis most interesting that the maximum amount of glycoside units per alkylgroup that can be added using known technology is 1.5. This means thatthe product is a mixture of mono and di functional product. This producthas the remaining fatty alcohol stripped off in an evaporative process.The resulting product is about 70% by weight of a product of a d.p. of1, about 21% by weight of a product of a d.p. of 2, about 7% by weightof a product having a d.p. of 3, and about 2% by weight of a productthat has a d.p. of 4.

We have surprisingly learned that taking the alkyl polyglycosidesproduced in the commercial process, with it's inherent lack of watersolubility and reacting it to make surface-active agents, results in aseries of products that are much more usable in many applications.Simply put, alkyl polyglycosides make much better hydrophobic rawmaterials than finished surface-active agents. When some or all of themany hydroxyl groups are converted into cationic groups outstandingconditioning and water solubility results.

SUMMARY OF THE INVENTION

Alkyl polyglycosides are complex products made by the reaction ofglucose and fatty alcohol. In dealing with the chemistry one talks aboutdegree of polymerization (the so called “d.p.”). In the case oftraditional alkyl polyglycosides the d.p. is around 1.4. This means thaton average thee is 1.4 units of glucose for each alkyl group. The factof the matter is that the resulting material is a mixture having anaverage of 1.4.

The specific structure of the product is hard to ascertain completelysince many positional isomers are possible, but two examples ofstructures are as follows;

Alkyl polyglycosides (d.p. 1)

Alkyl polyglycosides (d.p. 2)

It should be clear that if there is a 50/50 mixture of the d.p. 1 andd.p. 2 product, the resulting analytical data will show that on averagethere is a d.p. of 1.5. Saying that a molecule has a d.p. of 1.5 doesnot mean that each molecule has 1.5 glucose units on it.

One key aspects of the present invention relates to theheretofore-unappreciated fact that the rather hydrophobic alkylpolyglycosides contain on average five hydroxyl groups, one primary andthe other four secondary. The assumption that there is a large degree ofgroup specificity for the primary to react exclusively rather than thefour additional hydroxyl groups is simply not true. This means that ifon average only one of the five groups is reacted, there remains a verylarge concentration of reacting alkyl polyglycoside that has nofunctionality on it. Since the reactant with no functionalization remainwater insoluble, there needs to be at lease 2 and as many as 4 hydroxylgroups functionalized to get to the desired water-soluble product. Wehave observed that when between 2 and 5 groups are reacted, awater-soluble very useful product results. Therefore it is a preferredembodiment having between 2 and 5 of the hydroxyl groups functionalized.

Another key unappreciated fact in making the compounds of the presentinvention is the selection of the proper reagents to make the desiredproduct. Specifically, the reaction of the alkyl polyglycoside with acertain family of chloro compounds and related materials occurs undermild aqueous conditions and results in a mild cationic conditioneruseful in hair and skin care products.

DETAILED DESCRIPTION OF THE INVENTION

The compositions of the present invention are mixtures conform to thefollowing structures:

wherein;

R is alkyl having 8 to 22 carbon atoms;

R¹, R², R³ and R⁴ are independently selected from the group consistingof—CH₂CH(OH)CH₂—R¹²

-   -   and H, with the proviso that R¹, R², R³ and R⁴ are not all H;

R¹² is

M is selected from the group consisting of Na, K, and NH₄,

and

wherein;

R is alkyl having 8 to 22 carbon atoms;

R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, and R¹¹ are independently selected from thegroup consisting of;—CH₂CH(OH)CH₂—R¹²

-   -   and H, with the proviso that R⁵, R⁶, R⁷, R⁸, R⁹,R¹⁰ and R¹¹ are        not all H;

R¹² is

M is selected from the group consisting of Na, K, and NH₄.

Another aspect of the present invention is a process for conditioninghair and skin which comprises contacting the hair and skin with aneffective conditioning concentration of a composition conforming to thefollowing:

wherein;

R is alkyl having 8 to 22 carbon atoms;

R¹, R², R³ and R⁴ are independently selected from the group consistingof—CH₂CH(OH)CH₂—R¹²

-   -   and H, with the proviso that R¹, R², R³ and R⁴ are not all H;

R¹² is

M is selected from the group consisting of Na, K, and NH₄, and

wherein;

R is alkyl having 8 to 22 carbon atoms;

R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, and R¹¹ are independently selected from thegroup consisting of—CH₂CH(OH)CH₂—R¹²

-   -   and H, with the proviso that a R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰ and R¹¹        are not all H;

R¹² is

M is selected from the group consisting of Na, K, and NH₄.

Preferred Embodiment

In a preferred embodiment M is Na.

In a preferred embodiment M is K.

In a preferred embodiment M is NH₄.

The sulfosuccinate compound produced using the present invention, unlikethe starting alkyl polyglucoside, is an anionic surface-active agent. Itis water soluble, foams highly in water and possesses good detergencyproperties.

The sulfosuccinate of the present invention is very mild to the skin andeye and does not defat or dry the skin the way sodium lauryl sulfatedoes. This makes the compounds of the present invention highly desirablein the formulation of personal care products, most particularly babycare products and bath products.

The products of the present invention are anionic compounds that arefree of ethylene and propylene oxide. Consequently, they do not containany free ethylene oxide, dioxane or any other undesirable by-products.

Today's consumer of personal care products is keenly aware of thedesirability of having naturally derived, environmentally friendly cleanproducts. The compounds of the present invention are surprisinglyeffective in this area.

EXAMPLES Preparation of Alkyl Glycosides

Alkyl Glycosides are raw materials used to make the surface-activepolyglycoside derivatives of the present invention.

Saccharides useful in the process of making alkyl glycosides aresaccharides that can be alkylated in the “1” position, commonly referredto as “reducing saccharides”, or higher saccharides that can behydrolyzed to provide such a saccharide. These saccharides are typicallycomprised of aldo- or keto-hexoses or pentoses.

Examples of saccharides include glucose (dextrose), fructose, mannose,galactose, talose, allose, altrose, idose, arabinose, xylose, lyxose,and ribose. Examples of hydrolyzable saccharides that are a source ofreducing saccharides include starch, maltose, sucrose, lactose,maltotriose, xylobiose, mellibiose, cellobiose, raffinose, stachiose,methyl glycosides, butyl glycosides, levoglucosan, and1,6-anhydroglucofuranose.

The physical form of the saccharide may vary. The saccharide willtypically be in a fluid (as opposed to a solid) state, e.g. as a melt oran aqueous syrup, during at least a portion of the period of reaction,if not for a predominant portion of the period of the reaction.Crystalline (e.g. anhydrous or hydrates) or amorphous saccharide solidsin various particle sizes, e.g. granules, powders, etc., can be used,but the heating of the reaction medium may well fluidize at least aportion of a solid reactant, if not a predominant portion of thesaccharide reactant. Aqueous syrups of saccharides, typically atsaccharide solids of between about 10% and 90% dry solids by weight canalso be used. Indeed, the use of the hydrophobic catalysts of thisinvention should show the most improved results over conventionalcatalysts in the context of the use of aqueous syrup reactants ascompared with processes which employ solid saccharide reactants,particularly with respect to avoiding the formation of deleteriousamounts of polysaccharides and very high DP alkyl glycosides during theglycoside formation reaction.

The preferred saccharides are glucose, galactose, xylose and arabinose,or mixtures thereof, for reasons of availability, low cost, andconvenience. Glucose in the anhydrous crystalline form is preferred,although dextrose monohydrate, corn syrups of high dry solids (typically50% to 80% dry solids) and a high dextrose equivalence (D.E.) (typicallygreater than 90 D.E and most commonly 95 D.E.) can be commonly employed.Indeed, while the higher the purity of the dextrose source, the betterthe quality of the product (other things being equal), the catalysts ofthis invention allow the use of a lower purity dextrose source and yetyield a product of substantially equivalent quality as compared withprior catalysts. Because of the ready availability of glucose and itsoligomers, much of the remaining description is particularly suited tothe use of glucose in its various forms.

Alcohols useful in the process of this invention are hydroxyl-functionalorganic compounds capable of alkylating a saccharide in the “1”position. The alcohol can be naturally occurring, synthetic, or derivedfrom natural sources and/or derivatized. Examples include monohydricalcohols (more fully discussed below) and polyhydric alcohols (e.g.ethylene glycol, propylene glycol, polyethylene glycols, polypropyleneglycols, butylene glycol, glycerol, trimethylolpropane, pentaerythritol,polyester polyols, polyisocyanate polyols, and so on). Other examplesinclude aromatic alcohols such as benzyl alcohol, phenol, substitutedphenols (e.g. alkylphenols) and alkoxylates of each.

Preferred alcohols are monohydric alcohols containing from about 1 toabout 30 carbon atoms. They may be primary or secondary alcohols,straight or branched chain, saturated or unsaturated (e.g. allylalcohol, 2-ethylhexenyl alcohol and oleyl alcohol) alkyl or aralkylalcohols, ether alcohols, cyclic alcohols, or heterocyclic alcohols. Ingeneral, these alcohols have minimal solvent power for the saccharidemolecule. Examples of the monohydric alcohols which may be employed inthe present invention include methyl alcohol, isopropyl alcohol, butylalcohol, octyl alcohol, nonyl alcohol, decyl alcohol, dodecyl alcohol,tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecylalcohol, pentacosyl alcohol, oleyl alcohol, linoleyl alcohol, isoborneolalcohol, hydroabietyl alcohol, phenoxyethanol, phenoxypolyethoxyethanolcontaining five ethoxy groups, 2-methyl-7-ethyl-4-undecanol, andmixtures of one or more of the above.

A preferred group of alcohols are alkanols having the formula ROHwherein R represents an alkyl group having from 8 to 30 carbon atoms. Aparticularly preferred group of alcohols are those wherein R representsan alkyl radical having from 8 to 20, preferably 11 to 18, carbon atoms.The alkyls can be straight or branched chain.

Alkyl Glycoside Examples Example 1

A one-liter, four-necked, round-bottomed flask was equipped through itscenter neck with an overhead mechanical stirrer, through a second neckwith a distillation head fitted with an addition funnel and acondenser/receiver/vacuum take-off assembly, through a third neck fittedwith a three hole rubber stopper with a capillary nitrogen bleed, acalibrated mercury thermometer and a vacuum tight temperature controllerprobe, and on the fourth neck with a septum for sampling.

The flask was charged with 602.4 g (3.105 moles) of a commercial mixtureof C₁₁ to C₁₅ (98% C₁₂ and C₁₃) straight and branched alkanols (Neodol23 available form Shell Chemical Co.) and 136.6 g (0.69 moles) of acommercially available dextrose monohydrate (Staleydex 333, availablefrom A. E. Staley Mfg. Co. at 9.0% moisture). The slurry was heated at avacuum of 30 mm Hg (absolute). Water was released starting at about57.degree. C. and heating was continued until the slurry had reached110.degree. C. At this time 3.2 g (0.00345 mole of a commerciallyavailable mixture of 50% dinonylnaphthalenesulfonic acid in heptane(available from King Industries) was added as a catalyst and thetheoretical volume of water distilled at about a linear rate over 8hours. After stirring an additional hour, a stoichiometric amount ofaqueous NaOH (33% in H₂O) was added. An aliquot of the neutralizedreaction mixture (3.39 g, 1 g dissolved substance) was dissolved in atotal volume of 10 ml with 1:1 isopropanol:water. The pH of thissolution was 7.8.

The remainder of the reaction mixture was evaporated to a clear melt at200.degree. C. and 1 mm pressure using a Leybold-Heraeus Distact™ wipedfilm evaporator operating at a feed rate of 700 ml/hr.

The residue was analyzed using a combination of gas and liquidchromatographic techniques as well as NMR spectroscopy and was shown tocontain less than 0.2% free alcohol and less than 2% polar species(HPLC) and an NMR mole ratio of glucose rings to fatty chains of about1.4.

Example 2–8

The same one-liter, four-necked, round-bottomed flask was equippedthrough its center neck with an overhead mechanical stirrer, through asecond neck with a distillation head fitted with an addition funnel anda condenser/receiver/vacuum take-off assembly, through a third neckfitted with a three hole rubber stopper with a capillary nitrogen bleed,a calibrated mercury thermometer and a vacuum tight temperaturecontroller probe, and on the fourth neck with a septum for sampling.

The flask was charged with 3.105 moles of the specified alcohol and136.6 g (0.69 moles) of a commercially available dextrose monohydrate(Staleydex 333, available from A. E. Staley Mfg. Co. at 9.0% moisture).The slurry was heated at a vacuum of 30 mm Hg (absolute). Water wasreleased starting at about 57.degree. C. and heating was continued untilthe slurry had reached 110.degree. C. At this time 3.2 g (0.00345 moleof a commercially available mixture of 50% dinonylnaphthalenesulfonicacid in heptane (available from King Industries) was added as a catalystand the theoretical volume of water distilled at about a linear rateover 8 hours. After stirring an additional hour, a stoichiometric amountof aqueous NaOH (33% in H₂O) was added. An aliquot of the neutralizedreaction mixture (3.39 g, 1 g dissolved substance) was dissolved in atotal volume of 10 ml with 1:1 isopropanol:water. The pH of thissolution was 7.8.

The remainder of the reaction mixture was evaporated to a clear melt at200.degree. C. and 1 mm pressure using a Leybold-Heraeus Distact™ wipedfilm evaporator operating at a feed rate of 700 ml/hr.

The residue was analyzed using a combination of gas and liquidchromatographic techniques as well as NMR spectroscopy and was shown tocontain less than 0.2% free alcohol and less than 2% polar species(HPLC) and an NMR mole ratio of glucose rings to fatty chains of about1.4. The hydroxyl value was run on the resultant product and isindicated below.

Example Alkyl OH Value 2 C12H25 691.9 3 C10H21 741.8 4 C8H17 795.4 5C14H27 653.8 6 C18H37 584.4 7 C18H35 586.7 8 C20H42 555.1 9 C22H42 531.2

Alkyl Polyglycoside Surfactant Compounds

The introduction of the sulfosuccinate group into the molecule isaccomplished using the following intermediate;

M is selected from the group consisting of Na, K, and NH₄

This intermediate is made using the following reaction sequence;Glyceryl chlorohydrin is an item of commerce available commercially fromPhoenix Chemical in Somerville N.J. It conforms to the followingstructure;C₁—CH₂—CH(OH)CH₂OH

The reaction sequence is as follows;

The example shown uses Na₂SO₃ but, K₂SO₃, or (NH₄)₂SO₃ can be utilizedto round out the “M+” definitions.

The intermediate is then reacted with the alkyl polyglucoside under basecatalysis.

a mixture of;

wherein;

R is alkyl having 8 to 22 carbon atoms;

R¹, R², R³ and R⁴ are independently selected from the group consistingof—CH₂CH(OH)CH₂—R¹²

-   -   and H, with the proviso that R¹, R², R³ and R⁴ are not all H;

R¹² is

M is selected from the group consisting of Na, K, and NH₄,

and

wherein;

R is alkyl having 8 to 22 carbon atoms;

R¹, R², R³ and R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, and R¹¹ are independentlyselected from the group consisting of;—CH₂CH(OH)CH₂—R¹²

-   -   and H, with the proviso that R¹, R², R³. and R⁴ are not all H;

R¹² is

Preparation of the Intermediates

Additional aspect of the current invention is an intermediate conformingto the following structure;

Chloro Reactant General Procedure

In a suitable vessel, with heating, mixing and cooling capabilities, isadded the specified amount of chloroglycerin is added the specifiedamount of maleic anhydride. The reaction mass is heated to 80–90° C. Thereaction is exothermic and is controlled with cooling. The reactionprogress is followed by titrating acid value in water and inisopropanol. When the two values are within 2 units of acidity thereaction is considered complete.

In another vessel is added the specified amount of water and thespecified amount of the specified sulfite (M₂SO₃). This sulfite solutionis then added to the chloroglycerin/maleic anhydride reaction product.The reaction mass is then heated to 80–90° C. and held until theresidual sulfite ion concentration is vanishingly low. The intermediateis used without additional purification.

Chloroglycerin Maleic Anhydride M₂SO₃ Water Example Grams Grams M GramsGrams  9 10.1 13.0 Na 16.9 60.0 10 10.1 13.0 K 25.8 60.0 11 10.1 13.0NH₄ 14.0 60.0

Examples

General Procedure—To a flask equipped with agitation, heat, thermometerand nitrogen sparge is added the specified amount of the specified alkylpolyglycoside and enough water to make the final product have a solidsof 35% by weight. The alkyl polyglycoside is heated to melt. Next, thespecified amount of chloro reactant (examples 9–11) is added under goodagitation and nitrogen sparge. Next is added 0.5% sodium methylate. The% is by weight and is based upon the total amount of all materialsreacted. Nitrogen sparge is simply nitrogen bubbled through the liquidcontents of the flask. This keeps the color light, minimizing oxidationand color formation. The reaction mass is heated to 90–100° C., and isheld for 5–8 hours. Testing for generation of inorganic chloride followsthe reaction progress. Once the theoretical value is reached, thereaction is terminated and the product is used without additionalpurification.

Alkyl polyglycoside Chloro Reactant Example Example Grams Example Grams15 1 446.0  9 2,500 16 2 416.0 10 1,000 17 3 388.0 11 1,500 18 4 472.0 9 1,800 19 5 528.0 10 1,000 20 6 526.0 11 1,000 21 7 528.0  9 1,100 228 526.0 10 1,200

It will be clearly understood that the alkyl polyglycoside has onaverage five hydroxyl groups when the d.p. is 1.4. The phosphation caninclude all five, but in a more preferred embodiment includes betweenone and three hydroxyl groups. This ratio provides the best degree ofwater solubility. The most preferred number of hydroxyl groups to reactis 2.

The compounds of the invention range from clear yellow liquid anionicsurfactants.

The products made have outstanding detergency and foam properties aswell as emmoliency properties and humectant properties. Thesesurfactants are of particular importance for use in personal careapplications like bubble bath, shampoos and body wash. They are alsovery good additives for hard surface cleaners and detergent systems.

While the illustrative embodiments of the invention have been describedwith particularity, it will be understood that various othermodifications will be apparent to and can be readily made by thoseskilled in the art without departing from the spirit and scope of theinvention. Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the examples and descriptions set forthhereinabove but rather that the claims be construed as encompassing allthe features of patentable novelty which reside in the presentinvention, including all features which would be treated as equivalentsthereof by those skilled in the art to which the invention pertains.

1. A composition having components conforming to the following:

wherein; R is alkyl having 8 to 22 carbon atoms; R¹, R², R³ and R⁴ are independently selected from the group consisting of —CH₂CH(OH)CH₂—R¹² and H, with the proviso that R¹, R², R³ and R⁴ are not all H; R¹² is

M is selected from the group consisting of Na, K, and NH₄, and

wherein; R is alkyl having 8 to 22 carbon atoms; R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, and R¹¹ are independently selected from the group consisting of —CH₂CH(OH)CH₂—R¹² and H, with the proviso that R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰ and R¹¹ are not all H; R¹² is

M is selected from the group consisting of Na, K, and NH₄.
 2. A compound of claim 1 wherein M is Na.
 3. A compound of claim 1 wherein M is K.
 4. A compound of claim 1 wherein M is NH₄.
 5. A process for conditioning hair and skin which comprises contacting the hair and skin with an effective conditioning concentration of a composition conforming to the following:

wherein; R is alkyl having 8 to 22 carbon atoms; R¹, R², R³ and R⁴ are independently selected from the group consisting of —CH₂CH(OH)CH₂—R¹² and H, with the proviso that R¹, R², R³ and R⁴ are not all H; R¹² is

M is selected from the group consisting of Na, K, and NH₄, and

wherein; R is alkyl having 8 to 22 carbon atoms; R⁵R⁶, R⁷, R⁸, R⁹, R¹⁰, and R¹¹ are independently selected from the group consisting of —CH₂CH(OH)CH₂—R¹² R¹² is

and H, with the proviso that R⁵, R⁶, R⁷, R⁸, R⁹, and R¹⁰ are not all H; M is selected from the group consisting of Na, K, and NH₄.
 6. A process of claim 5 wherein M is Na.
 7. A process of claim 5 wherein M is K.
 8. A process of claim 5 wherein M is NH₄. 